Box lintel

ABSTRACT

A box lintel includes a hollow form defining an inner space. A foam material region is positioned in the inner space and adjacent to the hollow form so that the foam material region occupies a portion of the inner space and defines a volume for receiving masonry material. The amount of the foam material region positioned in the inner space is chosen to provide the box lintel with a desired weight.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to the masonry construction of openings, such as doorways, windows, and the like.

More particularly, the present invention relates to the formation of the lintels of openings, such as doorways, windows, etc., in masonry construction.

2. Related Art and Prior Art Statement

In the prior art, the construction of openings, such as doorways, windows, and the like, in masonry block walls is generally accomplished by defining the sides of the opening with upright lintel supports. Masonry blocks are then used to form the wall to approximately the desired height of the opening. A lintel is then placed between the supports to span the opening. The lintel is typically a box lintel, an elongated flat piece of metal, or even a steel frame. Courses of masonry blocks or bricks are then placed on the lintel and the wall is completed. However, there are several problems with prior art lintels.

One problem is that the lintel carries the weight of the masonry blocks positioned on it. Hence, the maximum allowable length of the lintel and, consequently, the size of the opening the lintel spans, is severely limited by the lintel and its ability to carry this weight. Even with the limitations of size, the lintel must be extremely rugged and heavy, which makes it very cumbersome and difficult to work with. Another problem with prior art lintels is that they are typically provided to the end user in predetermined sizes and/or shapes. Finally, the appearance of the prior art lintel is not esthetically pleasing in most instances. Accordingly, it is desirable to provide a new lintel that is easier to work with, rugged, yet lighter in weight, and more esthetically pleasing.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a box lintel with a hollow form defining an inner space. A foam material region is positioned in the inner space and adjacent to the hollow form so that the foam material region occupies a portion of the inner space and defines a volume for receiving masonry material. The amount of the foam material region positioned in the inner space is chosen to provide the box lintel with a desired weight.

The present invention also provides a box lintel incorporated in a masonry wall having an opening therethrough with upright supports defining each side of the opening. An elongated, hollow metal form is supported by the upright supports and positioned to span the opening. The metal form has an inner space defined by a lower wall, integrally formed side walls extending upwardly therefrom, and integrally formed partial upper walls extending inwardly from the side walls. The partial upper walls provide a flat upper load bearing surface for carrying a row of masonry blocks. A foam material region is positioned in the hollow metal form so that it occupies a portion of the inner space. The foam material region is adjacent to the hollow metal form. A masonry material region is positioned in the hollow metal form so that it occupies the rest of the inner space. The foam material region has a density less than a density of the masonry material region.

The present invention further provides a method of installing a box lintel. The method includes providing a masonry wall with an opening therethrough including upright supports defining each side of the opening. A hollow metal form defining an inner space is provided and a foam material region is positioned in the hollow metal form so that it occupies a portion of the inner space. The hollow metal form, with the foam material region therein, is positioned on the upright supports to span the opening.

These and other features, aspects, and advantages of the present invention will become better understood with reference to the following drawings, description, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the drawings:

FIG. 1 is a simplified perspective view of a box lintel in accordance with the present invention;

FIG. 2 is a simplified end view of the box lintel of FIG. 1;

FIG. 3 is a simplified perspective view of reinforcing bars and stirrups included in the box lintel of FIG. 1; and

FIG. 4 is a simplified perspective view of a portion of a masonry wall illustrating the box lintel of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 are simplified perspective and end views, respectively, of a box lintel 100 in accordance with the present invention. It should be noted that like reference characters indicate corresponding elements throughout the several view. Box lintel 100 has several advantages which make it useful. For example, box lintel 100 is light in weight so it can be easily moved from one location to another. This is particularly useful because box lintels are typically incorporated into masonry walls where they are positioned above ground level to span an opening extending through the wall. Hence, box lintel 100 is easier to work with because its light weight makes it easier and less cumbersome to lift up.

Another advantage of box lintel 100 is that it is strong, sturdy, and rugged so that it can support the masonry positioned thereon when completed. The strength and weight needed for box lintel 100 is generally determined by its length and, as will be discussed in more detail below, its strength, weight, and length can be adjusted by the end user for a particular application. Hence, box lintel 100 allows more flexibility in choosing these parameters and others. Finally, there is more flexibility in choosing the appearance of box lintel 100 so that the end user can choose an appearance that is esthetically pleasing to him or her.

In one embodiment, box lintel 100 includes an elongated, hollow metal form 110 having a lower wall 111 and integrally formed side walls 112 and 113 extending upwardly therefrom. Lintel 100 also includes integrally formed partial upper walls 114 and 115 extending inwardly from side walls 112 and 113, respectively. In this way, walls 111-115 define an inner space 152. Side walls 112 and 113 each have a height denoted as H₁ and lower wall 111 has a width denoted as W. In this specific embodiment, partial upper walls 114 and 115 each end in a short downwardly extending end portion 116 and 117, respectively, which extend generally toward lower wall 111. Downwardly extending end portions 116 and 117 can be omitted in some applications, but they are included in this example because of the extra weight bearing characteristics they provide.

Hollow metal form 110 can be constructed in many different ways and provided with many different shapes and sizes. In this example, metal form 110 is fabricated by bending an elongated metal sheet (preferably steel) longitudinally at substantially a 90° bend, designated 120, between lower wall 111 and side wall 112. A second, parallel, substantially 90° bend, designated 121, is formed between lower wall 111 and side wall 113. Third and fourth substantially 90° bends, designated 122 and 123, are formed between side wall 112 and upper wall 114 and between side wall 113 and upper wall 115, respectively. Each of bends 120-123 are formed parallel to the longitudinal axis of the metal sheet so that wall 112 is parallel to wall 113 and wall 111 is parallel to walls 114 and 115. In this way, walls 111-115 form a generally rectangularly shaped box. Additional bends are made to form downwardly directed end portions 116 and 117, if they are included. It should be noted, however, that the metal sheet can be bent or shaped to provide other desired shapes, such as rectangular, triangular, curved, etc. It will of course be understood by those skilled in the art that this particular embodiment of forming box lintel 100 is only one method and other methods and structures will occur to those skilled in the art. For example, all of the bends and shapes can be formed simultaneously or substantially at the same time, or the metal sheet can be extruded with the desired form.

In this example, metal form 110 can be formed in standard or general lengths in many different ways. In one way, metal form 110 can be fabricated in a particular standardized length chosen for a specific application, such as a door lintel or a window lintel. In another way, form 110 can be fabricated in a particular length which can later be cut to a desired length by the end user. As will be explained in more detail presently, box lintel 100 should be long enough to span the opening and strong enough support the structure of the masonry positioned thereon. However, it should also be light enough so that it can be easily moved and positioned in its desired location.

There are several ways to provide box lintel 100 with a desired weight and strength. One way is to fill inner space 152 of hollow metal form 110 with a foam material region 150 and a grout/mortar material region 151. In this way, the relative amounts of foam material and grout/mortar material positioned in inner space 152 can be chosen to provide a desired weight and strength for lintel 100. It should be noted that in some embodiments, portions of inner space 152 can be empty, but in this embodiment it is occupied with one of foam material and grout/mortar material for illustrative purposes.

Grout is generally used to fill cracks and/or crevices in masonry and mortar includes any of various bonding materials used in masonry. These materials are typically used in surfacing and plastering and can include a plastic mixture of cement or lime, sand, and water which hardens in place to bind together blocks, stones, or bricks. Here, it will be understood that grout, mortar, or any convenient masonry material, is herein referred to as grout/mortar. A convenient masonry material is generally a non-porous, hydraulic, and/or cementitious material.

A foam material is generally a porous material that is lighter in weight than the grout/mortar material, yet still strong and resilient. A porous material is one which has many cells or voids throughout its structure. The cells can be open so that they communicate with each other or they can be closed and filled with a gas, such as air. Examples of foam materials include a “polymeric foam” which includes polymeric materials that have been expanded in some way so as to form a porous material. Examples of polymeric foams include polyurethane foam, Styrofoam, and other conventional expandable polymeric foams. The foam material can also include additives such as fillers, fibers, or other additives which affect properties such as strength, weight, expansion, setting, finish, etc.

In this embodiment, foam material region 150 is positioned in inner space 152 so that it is adjacent to surfaces 161, 162, and 163 of walls 111, 112, and 113, respectively. Top portions of foam material region 150 are adjacent to surfaces 164 and 165 of partially extending walls 114 and 115, respectively. Foam material region 150 extends inwards from metal form 110 into inner space 152 where it terminates to form surfaces 160, 168, and 169. Here, surfaces 160, 168, and 169 are parallel to surfaces 161, 162, and 163, respectively. Grout/mortar material region 151 is then positioned in inner space 152 so that it is adjacent to surfaces 160, 168, and 169. Foam material region 150 provides rigidity to metal form 110 while maintaining low weight. Grout/mortar material region 151 provides the load bearing structure of metal form 110 when positioned in inner space 152.

The foam material can be applied or formed through conventional techniques or processes. The foam material can be applied in prefabricated configurations with a desired shape, size, and length so that it will fill the desired portion of inner space 152. In this embodiment, metal form 110 and foam material region 150 are prefabricated and shaped so that form 110 can receive foam material region 150 therein. In other embodiments, metal form 110 can be prefabricated in a desired shape and foam material region 150 can be sprayed or injected into inner space 152 so that it conforms to the shape of metal form 110. Material region 150 is then left to cure or harden so that it occupies a desired amount of space 152. In another embodiment, foam material region 150 can be prefabricated in a desired shape and metal form 110 can be made of a flexible material that is then bent and shaped to conform to the shape of foam material region 150.

As mentioned above, the foam and grout/mortar material are chosen to have different densities so that the relative amount of them in corresponding regions 150 and 151 can be adjusted to provide box lintel 100 with a desired weight and strength. For example, the weight and strength of box lintel 100 increases as the amount of the grout/mortar material in inner space 152 increases and the amount of foam material decreases. It is generally desirable to increase the amount of grout/mortar material in inner space 152 as the length of metal form 110 increases because lintel 100 has to be stronger to span a longer opening without bending too much or breaking.

Likewise, the weight and strength of box lintel 100 decreases as the amount of the grout/mortar material in inner space 152 decreases and the amount of foam material increases. It is generally desirable to decrease the amount of grout/mortar material in inner space 152 as the length of metal form 110 decreases because lintel 100 does not have to be as strong because the opening is shorter. Since in most embodiments, one or more modified masonry blocks 125 are positioned on load bearing surfaces 166 and 167 of upper walls 114 and 115, respectively. The relative amount of foam and grout/mortar material should also be chosen to support the weight of blocks 125 and any other structure positioned thereon blocks 125. However, metal form 110 should also be light enough so that it can be moved and positioned in its desired location with ease.

In this embodiment, modified masonry blocks 125 are the type having opposed vertical side walls, or faces, and a plurality of vertical openings, or air spaces, extending therethrough formed by webbing extending horizontally between the vertical side walls. They also have a channel 139 extending from one end to the other between opposite faces thereof and through the webbing. Each block has a height denoted as H₂ and a width W, which is the same or substantially equal to the width of lower wall 111, although this is not essential. Modified masonry blocks 125 can be purchased or they can be formed by simply removing a portion of the webbing from a standard masonry block.

FIG. 3 is a simplified perspective view of one embodiment of another way of increasing the strength of box lintel 100 in accordance with the present invention. In this embodiment, box lintel 100 includes reinforcing bars which extend through box lintel 100 and channel 139 of modified masonry blocks 125 (FIGS. 1 and 2). Here, reinforcing bars 140 and 141 are positioned in inner space 152 so that they extend through grout/mortar material region 151 (FIG. 2). Similarly, reinforcing bars 142 and 143 are positioned so that they extend through channel 139 of blocks 125 (FIG. 1). A reinforcing bar 144 is coupled between reinforcing bars 140,141 and reinforcing bars 142,143. One end of reinforcing bar 144 is coupled to bars 140,141 by a stirrup 147 and the opposed end is coupled to bars 142,143 by a stirrup 148. In this example, a plurality of reinforcing bars 144 are provided along the lengths of bars 140-143.

In this embodiment, reinforcing bars 140-144 are made of elongated hard materials such as steel. In this example, reinforcing bar 144 is L-shaped and includes an elongated main member 145 which extends between bars 140,141 and bars 142,143 and a secondary member 146 which extends at a substantially 900 angle from main member 145. In this particular example, secondary member 146 extends underneath bar 141 and stirrup 147 couples member 146 thereto bars 140,141. It should be noted that other configurations of reinforcing bars and stirrups can be used to provide added strength to box lintel 100, but only one example is shown here for simplicity. For example, in other embodiments, one reinforcing bar can extend through blocks 125 and another reinforcing bar can extend through grout/mortar material region 151 and they can be coupled together with stirrups or ties spaced along the length of the reinforcing bars.

FIG. 4 is a simplified perspective view of a portion of a masonry wall 134 utilizing box lintel 100 in accordance with the present invention. In this embodiment, a pair of upright masonry supports 135 and 136 are provided to define the sides of an opening 131 which extends through wall 134. Upright masonry supports 135 and 136 are either formed by the edges of masonry blocks or by additional bearing material (not shown) which may be incorporated in a well known manner. Masonry wall 134 is made of standard masonry blocks 137 stacked in ways known in the art. Masonry blocks 137 can be similar to masonry blocks 125 except they generally do not have channel 139 extending therethrough. Blocks 125 and 137 can be formed of material known in the art, such as molded concrete, but it will be understood that any of the other well-known masonry materials, such as bricks or stones, can also be used.

In this embodiment, lintel support blocks 130 and 132 are positioned adjacent to masonry supports 135 and 136, respectively, at a height desired for opening 131. Lintel support blocks 130 and 132 can be the same or similar to masonry blocks 125 or 137. To complete opening 131, box lintel 100 is provided and positioned so that it is supported by lintel support blocks 130 and 132. In this way, metal form 110 spans space 131 by extending between masonry supports 135 and 136. Masonry blocks 125 are then provided and laid on load bearing surfaces 166 and 167 of form 110 so that a row of modified masonry blocks 125 extends over opening 131.

In this embodiment, channels 139 in blocks 125 and portions of inner space 152 not occupied by foam material region 150 are then filled with grout/mortar material (FIG. 2) to form grout/mortar material region 151 which extends up into blocks 125. Here it should be understood that in normal masonry construction, it may not be necessary to completely fill all of blocks 125 with grout/mortar. However, it has been found that the strength of form 110 is substantially increased as the amount of mortar in form 110 and blocks 125 is increased. Further, building and/or fire codes may require that any structural steel or reinforcing bars included in a masonry wall be surrounded by grout/mortar. In this embodiment, the structural steel is reinforcing bars 140-143 surrounded by grout/mortar 151. The sheet steel of metal form 110 is not structural and need not be surrounded to meet code. Additional standard masonry blocks 137 are then provided and positioned on and around blocks 125 until masonry wall 134 is completed.

It should be understood that in some embodiments, solid masonry, such as solid blocks, bricks, or stones, can be used instead of modified masonry blocks 125 or standard masonry blocks 137. In these embodiments, it may be desirable to fill form 110 with grout/mortar and then place the solid blocks on load bearing surfaces 166 and 167. Hence, the steps of laying mortar and filling the openings with grout/mortar can be performed in any desired order that is convenient for the specific application and the type of masonry used.

During or after the construction of masonry wall 134, some plastering or grout/mortar may be desired on its outer 'surface to give the masonry opening a more esthetic appearance. To this end, walls 112 and/or 113 of hollow metal form 110 can include a regular pattern of small openings extending therethrough to provide a grip or anchor for mortar/plaster applied to the outer surface of form 110. In some specific applications the openings may not be needed or desirable (e.g. lintels which are to be simply painted) and in such applications the openings may be omitted. For simplicity of the drawing, the openings have been omitted.

Thus, metal form 110, foam material region 150, and grout/mortar material region 151 cooperate to form box lintel 100 which has flexible design characteristics. The design characteristics are flexible because box lintel 100 can be provided with a desired weight, strength, shape, and length. Hence, it can be made to be extremely strong while still being light and easy to work with. Further, box lintel 100 is relatively inexpensive and can be formed at substantially any reasonable length without requiring special manufacturing or components. In addition, box lintel 100 can be constructed utilizing a variety of materials (e.g. different blocks or masonry, etc.) on its outside surface so that it will be esthetically pleasing.

Various modifications and changes to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art. For example, form 110 and/or the box lintel can be fabricated in a variety of ways while still performing the stated functions. Further, a variety of different masonry materials may be utilized and the walls may be fabricated in a variety of somewhat modified and/or interchanged steps.

The foregoing is given by way of example only. Other modifications and variations may be made by those skilled in the art without departing from the scope of the invention as defined by the following claims.

Having fully described and disclosed the present invention and preferred embodiments thereof in such clear and concise terms as to enable those skilled in the art to understand and practice same, the invention claimed is: 

1. A box lintel, comprising: a hollow form defining an inner space; and a foam material region positioned in the inner space and adjacent to the hollow form so that the foam material region occupies a portion of the inner space and defines a volume for receiving masonry material.
 2. The lintel of claim 1, further including masonry material positioned in the volume defined by the foam material region.
 3. The lintel of claim 2, wherein an amount of the foam material region and the masonry material positioned in the inner space is chosen to provide the box lintel with a desired strength.
 4. The lintel of claim 1, wherein the hollow form is flexible and the foam material region is rigid.
 5. The lintel of claim 2, further including an elongated reinforcing bar positioned in the inner space and extending through the masonry material.
 6. The lintel of claim 1, wherein a portion of the hollow form is separated from the masonry material by the foam material region.
 7. The lintel of claim 1, wherein the foam material region is less dense than the masonry material.
 8. A box lintel incorporated in a masonry wall, comprising: a masonry wall with an opening therethrough including upright supports defining each side of the opening; an elongated, hollow metal form having an inner space defined by a lower wall, integrally formed side walls extending upwardly therefrom, the form having integrally formed partial upper walls extending inwardly from the side walls, the partial upper walls providing a flat upper load bearing surface for carrying a row of masonry blocks, the hollow metal form being supported by the upright supports and positioned to span the opening; a foam material region positioned in the hollow metal form so that it occupies a portion of the inner space, the foam material region being adjacent to the hollow metal form; and a masonry material region positioned in the hollow metal form so that it occupies the rest of the inner space, the foam material region having a density less than a density of the masonry material region.
 9. The lintel of claim 8, wherein the masonry material region includes grout/mortar.
 10. The lintel of claim 8, wherein the metal form is flexible so that it conforms to the shape of the foam material region.
 11. The lintel of claim 8, further including a first course of partially hollow masonry positioned on the partial upper walls of the metal form.
 12. The lintel of claim 11, further including first and second elongated reinforcing bars extending through the masonry material region and the first course of partially hollow masonry, respectively, the first and second elongated reinforcing rods being coupled together.
 13. The lintel of claim 11, wherein the masonry material region extends into the first course of partially hollow masonry to increase the load bearing strength of the box lintel.
 14. The lintel of claim 8, wherein the amount of the foam and masonry material regions positioned in the inner space is chosen to provide the box lintel with a desired weight and strength.
 15. A method of installing a box lintel, comprising: providing a masonry wall with an opening therethrough including upright supports defining each side of the opening; providing a hollow metal form defining an inner space; positioning a foam material region in the hollow metal form so that it occupies a portion of the inner space; and positioning the hollow metal form, with the foam material region therein, on the upright supports to span the opening.
 16. The method of claim 15, further including providing a masonry material in the inner space.
 17. The method of claim 16, further including choosing the amount of the foam material region and the masonry material to provide the box lintel with a desired weight.
 18. The method of claim 16, wherein the foam material region defines a volume for receiving the masonry material.
 19. The method of claim 15, further including positioning masonry blocks on the hollow metal form.
 20. The method of claim 16, further including providing a reinforcing bar which extends through the masonry material. 